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Somatostatin Receptor Scintigraphy
An octreotide scan is a type of SPECT scintigraphy used to find carcinoid, pancreatic neuroendocrine tumors, and to localize sarcoidosis. It is also called somatostatin receptor scintigraphy (SRS). Octreotide, a drug similar to somatostatin, is radiolabeled with indium-111, and is injected into a vein and travels through the bloodstream. The radioactive octreotide attaches to tumor cells that have receptors for somatostatin (i.e. gastrinoma, glucagonoma, etc.). A gamma camera detects the radioactive octreotide, and makes pictures showing where the tumor cells are in the body, typically by a SPECT technique. A technetium-99m based radiopharmaceutical kit is also available. Octreotide scanning is reported to have a sensitivity between 75% and 100% for detecting pancreatic neuroendocrine tumors. Instead of gamma-emitting 111In, certain octreotide derivatives such as edotreotide (DOTATOC) or DOTATATE are able to be linked by chelation to positron-emitting isotopes such as gallium-68 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectopia (medicine)
An ectopia () is a displacement or malposition of an organ or other body part, which is then referred to as ectopic ({{IPAc-en, ɛ, k, ˈ, t, ɒ, p, ɪ, k). Most ectopias are congenital, but some may happen later in life. Examples *Ectopic ACTH syndrome, also known as small-cell carcinoma. *Ectopic calcification, a pathologic deposition of calcium salts in tissues or bone growth in soft tissues * Cerebellar tonsillar ectopia, aka Chiari malformation, a herniation of the brain through the foramen magnum, which may be congenital or caused by trauma. * Ectopic cilia, a hair growing where it isn't supposed to be, commonly an eyelash on an abnormal spot on the eyelid, distichia *Ectopia cordis, the displacement of the heart outside the body during fetal development * Ectopic enamel, a tooth abnormality, where enamel is found in an unusual location, such as at the root of a tooth *Ectopic expression, the expression of a gene in an abnormal place in an organism * Ectopic hormone, a horm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Camera
A gamma camera (γ-camera), also called a scintillation camera or Anger camera, is a device used to image gamma radiation emitting radioisotopes, a technique known as scintigraphy. The applications of scintigraphy include early drug development and nuclear medical imaging to view and analyse images of the human body or the distribution of medically injected, inhaled, or ingested radionuclides emitting gamma rays. Imaging techniques Scintigraphy ("scint") is the use of gamma cameras to capture emitted radiation from internal radioisotopes to create two-dimensional images. SPECT (single photon emission computed tomography) imaging, as used in nuclear cardiac stress testing, is performed using gamma cameras. Usually one, two or three detectors or heads, are slowly rotated around the patient's torso. Multi-headed gamma cameras can also be used for positron emission tomography (PET) scanning, provided that their hardware and software can be configured to detect "coincidences" (nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravenous
Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use. The intravenous route is the fastest way to deliver medications and fluid replacement throughout the body as they are introduced directly into the circulatory system and thus quickly distributed. For this reason, the intravenous route of administration is also used for the consumpti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer Staging
Cancer staging is the process of determining the extent to which a cancer has developed by growing and spreading. Contemporary practice is to assign a number from I to IV to a cancer, with I being an isolated cancer and IV being a cancer that has spread to the limit of what the assessment measures. The stage generally takes into account the size of a tumor, whether it has invaded adjacent organs, how many regional (nearby) lymph nodes it has spread to (if any), and whether it has appeared in more distant locations (metastasized). The staging system is not applicable to astrocytoma, which is instead expressed as "grade I–IV". Grade IV astrocytoma, more commonly referred to as glioblastoma multiforme, is a universally fatal primary brain cancer most commonly seen in the seventh decade of life. TNM staging system Cancer staging can be divided into a clinical stage and a pathologic stage. In the TNM (Tumor, Node, Metastasis) system, clinical stage and pathologic stage are deno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detectnet
Copper (64Cu) oxodotreotide or Copper Cu 64 dotatate, sold under the brand name Detectnet, is a radioactive diagnostic agent indicated for use with positron emission tomography (PET) for localization of somatostatin receptor positive neuroendocrine tumors (NETs) in adults. Common side effects include nausea, vomiting and flushing. It was approved for medical use in the United States in September 2020. History The U.S. Food and Drug Administration (FDA) approved copper 64Cu dotatate based on data from two trials that evaluated 175 adults. Trial 1 evaluated adults, some of whom had known or suspected NETs and some of whom were healthy volunteers. The trial was conducted at one site in the United States (Houston, TX). Both groups received copper 64Cu dotatate and underwent PET scan imaging. Trial 2 data came from the literature-reported trial of 112 adults, all of whom had history of NETs and underwent PET scan imaging with copper 64Cu dotatate. The trial was conducted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallium Scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gallium nitrate may be used. The form of salt is not important, since it is the freely dissolved gallium ion Ga3+ which is active. Both 67Ga and 68Ga salts have similar uptake mechanisms. Gallium can also be used in other forms, for example 68Ga-PSMA is used for cancer imaging. The gamma emission of gallium-67 is imaged by a gamma camera, while the positron emission of gallium-68 is imaged by positron emission tomography (PET). Gallium salts are taken up by tumors, inflammation, and both acute and chronic infection, allowing these pathological processes to be imaged. Gallium is particularly useful in imaging osteomyelitis that involves the spine, and in imaging older and chronic infections that may be the cause of a fever of unknown origin. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PET-CT
Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a nuclear medicine technique which combines, in a single gantry, a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner, to acquire sequential images from both devices in the same session, which are combined into a single superposed ( co-registered) image. Thus, functional imaging obtained by PET, which depicts the spatial distribution of metabolic or biochemical activity in the body can be more precisely aligned or correlated with anatomic imaging obtained by CT scanning. Two- and three-dimensional image reconstruction may be rendered as a function of a common software and control system. PET-CT has revolutionized medical diagnosis in many fields, by adding precision of anatomic localization to functional imaging, which was previously lacking from pure PET imaging. For example, many diagnostic imaging procedures in oncology, surgical planning, radia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper-64
Copper-64 (64Cu) is a positron and beta emitting isotope of copper, with applications for molecular radiotherapy and positron emission tomography. Its unusually long half-life (12.7-hours) for a positron-emitting isotope makes it increasingly useful when attached to various ligands, for PET and PET-CT scanning. Properties 64Cu has a half-life of 12.7 hours and decays 17.9% by positron emission to 64Ni, 39.0% by beta decay to 64Zn, 43.1% by electron capture to 64Ni, and 0.475% gamma radiation/internal conversion. These emissions are 0.579 MeV, 0.653 MeV and 1.35 MeV for beta minus, positron, and gamma respectively. The oxidation states of copper in biology are I and II since Cu3+ is too powerful to exist in biochemical systems. Furthermore, copper(I) exists as a strong complex in aqueous solution and is not often seen. Copper(II) forms mononuclear complexes that are paramagnetic and prefers ligands of sulfur and nitrogen. Copper is essential in the human body as both a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallium-68
Natural gallium (31Ga) consists of a mixture of two stable isotopes: gallium-69 and gallium-71. The most commercially important radioisotopes are gallium-67 and gallium-68. Gallium-67 (half-life 3.3 days) is a gamma-emitting isotope (the gamma ray emitted immediately after electron capture) used in standard nuclear medical imaging, in procedures usually referred to as gallium scans. It is usually used as the free ion, Ga3+. It is the longest-lived radioisotope of gallium. The shorter-lived gallium-68 (half-life 68 minutes) is a positron-emitting isotope generated in very small quantities from germanium-68 in gallium-68 generators or in much greater quantities by proton bombardment of 68Zn in low-energy medical cyclotrons, for use in a small minority of diagnostic PET scans. For this use, it is usually attached as a tracer to a carrier molecule (for example the somatostatin analogue DOTATOC), which gives the resulting radiopharmaceutical a different tissue-uptake specificity from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOTATATE
DOTA-TATE (DOTATATE, DOTA-octreotate, oxodotreotide, DOTA-(Tyr3)-octreotate, and DOTA-0-Tyr3-Octreotate) is an eight amino acid long peptide, with a covalently bonded DOTA bifunctional chelator. DOTA-TATE can be reacted with the radionuclides gallium-68 (T1/2 = 68 min), lutetium-177 (T1/2 = 6.65 d) and copper-64 (T1/2 = 12.7 h) to form radiopharmaceuticals for positron emission tomography (PET) imaging or radionuclide therapy. 177Lu DOTA-TATE therapy is a form of peptide receptor radionuclide therapy (PRRT) which targets somatostatin receptors (SSR). In that form of application it is a form of targeted drug delivery. Chemistry and mechanism of action DOTA-TATE is a compound containing tyrosine3-octreotate, an SSR agonist, and the bifunctional chelator DOTA (tetraxetan). SSRs are found with high density in numerous malignancies, including CNS, breast, lung, and lymphatics. The role of SSR agonists (i.e. somatostatin and its analogs such as octreotide, somatuline and va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edotreotide
Edotreotide (USAN, also known as (DOTA0- Phe1- Tyr3) octreotide, DOTA-TOC, DOTATOC) is a substance which, when bound to various radionuclides, is used in the treatment and diagnosis of certain types of cancer. When used therapeutically it is an example of peptide receptor radionuclide therapy. Yttrium-90 A phase I clinical trial of yttrium-90 labelled edotreotide concluded in 2011, aiming to investigated effects in young cancer patients (up to 25 years of age). Specific cancers being included in the trial include neuroblastoma, childhood brain tumours and gastrointestinal cancer. A phase II trial for the use of 90Y DOTA-TOC for patients with metastatic carcinoid, where octreotide treatment was no longer effective, also reported results in 2010. : Lutetium-177 Lutetium-177 labelled edotreotide (177Lu-DOTA-TOC), with the trade name Solucin, is the subject of a phase 3 clinical trial for treatment of GEP-NETs. It was granted orphan drug designation by the European Medicines Age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensitivity And Specificity
''Sensitivity'' and ''specificity'' mathematically describe the accuracy of a test which reports the presence or absence of a condition. Individuals for which the condition is satisfied are considered "positive" and those for which it is not are considered "negative". *Sensitivity (true positive rate) refers to the probability of a positive test, conditioned on truly being positive. *Specificity (true negative rate) refers to the probability of a negative test, conditioned on truly being negative. If the true condition can not be known, a " gold standard test" is assumed to be correct. In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. If the goal is to return the ratio at w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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